Features of the device
Fig. 2.1. Block of cylinders of the engine
The block of cylinders of the engine is shown on
The block of cylinders is cast from the special low-alloyed cast iron. Diameters of cylinders are broken into classes. The class of the cylinder is branded on the bottom plane of the block of cylinders.
Possibility of boring of cylinders under the repair pistons increased on diameter is provided.
Covers of radical bearings are processed together with the block of cylinders therefore they are not interchangeable and for distinction have labels of an external surface.
Carefully wash up the block of cylinders, clear lubricant channels.
Having blown and having dried the compressed air, examine the block of cylinders. Cracks in any places of the block of cylinders are not allowed.
If there is a suspicion on hit of cooling liquid in an engine case, check at the special stand tightness of the block of cylinders. For this purpose, having muffled openings of a cooling shirt of the block of cylinders, submit to it water of room temperature under the pressure of 0,3 MPas (3 kgfs/cm
). During 2 mines it should not be observed leakages of water from the block.
If oil gets to cooling liquid, without complete dismantling of the engine check, whether there are no cracks at the block of cylinders in zones of oil channels. For this purpose merge liquid from cooling system, remove a head of the block of cylinders, fill a shirt of cooling of the block of cylinders with water and submit the compressed air to the vertical oil canal of the block of cylinders. In case of vials of air in the water filling a shirt of cooling, replace the block of cylinders.
Check the plane of the socket of the block of cylinders a block head a ruler and a set щупов. The ruler is established on plane diagonals in the middle, in the longitudinal direction and across, the admission of planeness makes 0,15 mm.
Measure diameter of each cylinder in the top, average and bottom its parts parallel to an axis of a cranked shaft.
Measure diameter of each cylinder in the top, average and bottom its parts perpendicular to an axis of a cranked shaft.
The Konusnost of the cylinder is calculated as a difference between top and bottom in diameters, ovality – as a difference between parallel and perpendicular measurements.
If the received results do not coincide with technical requirements, address to experts.
Step wear in the top part of the cylinder is removed by means of development.
In spare parts pistons of four repair sizes are delivered.
Repair sizes and marking of pistons:
increased by 0,25 mm..... 0,25
increased by 0,50 mm..... 0,50
increased by 0,75 mm..... 0,75
increased by 1,00 mm..... 1,00
When boring cylinders till the repair size it is necessary to keep a demanded gap between pistons of the repair size and cylinders and to establish pistons of the identical repair size.
Diameter of the piston is measured at distance of 47 mm from the piston bottom at right angle to lugs.
Gap between the piston and the cylinder of the engine, mm:
in working volume of 1,3/1,1 l..... 0,02–0,04
in working volume of 1,5 l..... 0,02–0,04
in working volume of 1,6 l..... 25–0,045